The field of the invention is electrical test systems.
The use of flexible substrates in the production of interconnects and circuits is becoming more and more prevalent. Such devices often comprise at least one flexible panel having conductive layers on two outer, opposing surfaces. In order to verify that such devices were properly manufactured, it is desirable to subject such panels to testing. However, testing of flexible panels tends to be a difficult and time consuming process.
A potential method of testing involves the use of test probes to establish a voltage or cause a current to flow between test points on opposite sides of the panel. This method tends not to work on flexible panels due to flexing of the panel during testing. Another method of testing involves laying the panel on a conductive test surface, using a test probe to apply a voltage or current to a test point of the panel and measuring the corresponding change in voltage and/or current between the test point and the test surface. When such methods are used with flexible panels, problems with poorly established or broken flow paths between the test point and test surface caused or related to the panel flexing away from the test surface are sometimes encountered. Methods involving probing from one side of the panel with conductive material shorting the opposite side are not reliable as the panel with its conductive layers is not sufficiently compliant.
Thus, there is a continuing need for new methods and devices to facilitate the testing of flexible substrate based circuits and interconnects.
The present invention is directed to a vacuum chuck with a conductive circuit embedded onto it""s surface wherein the chuck provides a reliable conductive path for electrical testing as well as reliable and uniform mechanical support over entire area of the flexible panel. In a preferred embodiment, the chuck comprises a fine grain porous alumina ceramic base having a surface coated with conductive material wherein the coating is thin enough that it does not block the air evacuation path, and is etched or otherwise formed into a conductive pattern to facilitate testing of a panel.
Various objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention, along with the accompanying drawings in which like numerals represent like components.